| 摘要 |
<p>A flat bed printer, in which positions where a printing head impacts a platen are distributed over a whole peripheral region of the cylindrical platen to thereby prevent deterioration of the platen. Drive shafts for a paper feed roller, the platen and a tractor are operatively connected to one another by means of a gear train to be driven by a motor. Gear ratios of respective gears in the gear train are selected so that the paper feed roller, the platen and the tractor accord with one another in peripheral speed. The platen revolves in synchronism with a feed speed of the paper feed roller and further with a feed speed of sheets fed by the tractor, and positions where the printing head impacts the platen are distributed over the whole peripheral region of the platen. The printer is provided with an approaching/separating mechanism and a pressing force varying mechanism for a pressure roller cooperating with the paper feed roller, a sheet conveying path switching mechanism for switching a conveying path in accordance with a continuous form and a cut form, and a mechanism for adjusting a gap between the printing head and the platen.</p> |
